In this work, we build on our earlier results and accomplishments in understanding, modeling and controlling underwater glider dynamics (YIP Grant # N00014-98-1-0649). The focus is on dedicated gliding vehicles that have the ability to change mass (or volume) for buoyancy control and to redistribute mass (and possibly control a rudder) for attitude control. The framework consists of a dynamical...

It has been known for decades that bacteria locomote over surfaces, but the mechanisms that power motility have been unclear. Recent experiments have begun to explain two modes of surface motility. Twitching or social gliding motility is powered by the retraction of type IV pili. Adventurous gliding motility is powered by the rearward secretion of carbohydrate slime. In both cases, cell movemen...

We consider the Banach-Mackey property for pairs of vector spaces E and E′ which are in duality. Let A be an algebra of sets and assume that P is an additive map from A into the projection operators on E. We define a continuous gliding hump property for the map P and show that pairs with this gliding hump property and another measure theoretic property are Banach-Mackey pairs,i.e., weakly bound...

Locomotor activity by diving marine mammals is accomplished while breath-holding and often exceeds predicted aerobic capacities. Video sequences of freely diving seals and whales wearing submersible cameras reveal a behavioral strategy that improves energetic efficiency in these animals. Prolonged gliding (greater than 78% descent duration) occurred during dives exceeding 80 meters in depth. Gl...

Combining transmission electron microscopes and density functional theory calculations, we report the nucleation and growth mechanisms of room temperature rolling induced face-centered cubic titanium (fcc-Ti) in polycrystalline hexagonal close packed titanium (hcp-Ti). Fcc-Ti and hcp-Ti take the orientation relation: 〈0001〉hcp||〈001〉fcc and , different from the conventional one. The nucleation ...

Gliding of microtubule filaments on surfaces coated with the motor protein kinesin has potential applications for nano-scale devices. The ability to guide the gliding direction in three dimensions allows the fabrication of tracks of arbitrary geometry in space. Here, we achieve this by using kinesin-coated glass wires of micrometer diameter range. Unlike previous methods in which the guiding tr...

It has been known for decades that bacteria locomote over surfaces, but the mechanisms that power motility have been unclear. Recent experiments have begun to explain two modes of surface motility. Twitching or social gliding motility is powered by the retraction of type IV pili. Adventurous gliding motility is powered by the rearward secretion of carbohydrate slime. In both cases, cell movemen...

Myxococcus xanthus cells exhibit directed motility up phosphatidylethanolamine (PE) gradients, and we suggest that PE behaves as a chemoattractant. Computer-assisted stop-motion digital microscopy was used to record cell movements in slide culture. PE decreased cellular reversal frequency with molecular specificity that was correlated with the fatty acid composition. Synthetic dilauroyl (di C12...

We consider the ICP (iterative closest point) algorithm, which may in general be used for moving ‘active’ elements such as curves and surfaces towards geometric objects whose distance field is computable. We show how it may be accelerated, and how it can be applied to the design of near-Euclidean near-contact spline motions. One particular application of this concept is the modeling of milling ...